he petitioned rhee's office. y vaent event ally the phony evaluation was removed. >> there's never going to be a perfect tool. if the bar is that if it has bugs in it, we can't implement it. then you will literally never implement. >> reporter: in late july final evaluation scores were released. rhee fired 75 teachers for poor performance. 671 more were deemed minimally effective and given one year to improve or lose their jobs. that's nearly 20% of rhee's teaching force that could be out of work one year from now. does it surprise you that those numbers are so high? >> i didn't proffer any guesses at the front end to say it will be this percentage or that percentage. but when we took control of this school district in 2007, 8% of the 8th graders were operating on grade level in mathematics. 8%. and if you would have looked at the performance evaluations of the adults in the system at the same time, you would have seen that 95% of them were being rated as doing a good job. how can you possibly have a system where